Rheolytic thrombectomy with percutaneous coronary intervention for infarct size reduction in acute myocardial infarction: 30-day results from a multicenter randomized study

Impact of thrombus aspiration on left ventricular remodeling and function in patients with ST-segment elevation myocardial infarction: A meta-analysis of randomized controlled trials

BACKGROUND

Routine thrombus aspiration (TA) does not improve clinical outcomes in patients with ST-segment-elevation myocardial infarction (STEMI), although data from meta-analyses suggest that patients with high thrombus burden may benefit from it. The impact of TA on left ventricular (LV) functional recovery and remodeling after STEMI remains controversial. We aimed to pool data from randomized controlled trials (RCTs) on the impact of TA on LV function and remodeling after primary percutaneous coronary intervention (pPCI).

METHODS

PubMed and CENTRAL databases were scanned for eligible studies. Primary outcome measures were: LV ejection fraction (LVEF), LV end diastolic volume (LVEDV), LV end systolic volume (LVESV) and wall motion score index (WMSI). A primary pre-specified subgroup analysis was performed comparing manual TA with mechanical TA.

RESULTS

A total of 28 studies enrolling 4990 patients were included. WMSI was lower in TA group than in control (mean difference [MD] -0.11, 95% confidence interval [CI] -0.19 to -0.03). A greater LVEF (MD 1.91, 95% CI 0.76 to 3) and a smaller LVESV (MD -6.19, 95% CI -8.7 to -3.6) were observed in manual TA group compared to control. Meta regressions including patients with left anterior descending artery (LAD) involvement showed an association between TA use and the reduction of both LVEDV and LVESV (z = -2.13, p = 0.03; z = -3.7, p < 0.01) and the improvement in myocardial salvage index (z = 2.04, p = 0.04).

CONCLUSION

TA is associated with improved LV function. TA technique, total ischemic time and LAD involvement appears to influence TA benefit on post-infarction LV remodeling.

Microvascular Obstruction in Acute Myocardial Infarction, a Potential Therapeutic Target

Microvascular obstruction (MVO) is a recognised phenomenon following mechanical reperfusion in patients presenting with ST-segment elevation myocardial infarction (STEMI). Invasive and non-invasive modalities to detect and measure the extent of MVO vary in their accuracy, suggesting that this phenomenon may reflect a spectrum of pathophysiological changes at the level of coronary microcirculation. The importance of detecting MVO lies in the observation that its presence adds incremental risk to patients following STEMI treatment. This increased risk is associated with adverse cardiac remodelling seen on cardiac imaging, increased infarct size, and worse patient outcomes. This review provides an outline of the pathophysiology, clinical implications, and prognosis of MVO in STEMI. It describes historic and novel pharmacological and non-pharmacological therapies to address this phenomenon in conjunction with primary PCI.

Mechanisms of the "No-Reflow" Phenomenon After Acute Myocardial Infarction: Potential Role of Pericytes

Pericytes contract during myocardial ischemia resulting in capillary constriction and no reflow. Reversing pericyte contraction pharmacologically reduces no reflow and infarct size. These findings open up an entire new venue of research aimed at altering pericyte function in myocardial ischemia and infarction.

Dual Role of Guide Extension Catheters for the Management of High Thrombus Burden in STEMI: Case Report and Mini Review

High thrombus burden in ST segment elevation myocardial infarction (STEMI) patients increases the risk of adverse events. In this report, we review current strategies for high thrombus burden and present a case report with the combination of two different techniques: aspiration through a guide extension catheter followed by local intracoronary thrombolysis with 'marinade' technique.

Prognostic Role of Residual Thrombus Burden Following Thrombectomy: Insights From the TOTAL Trial

BACKGROUND

It is unclear whether more effective forms of thrombus removal than current aspiration catheters would lead to improved outcomes. We sought to evaluate the prognostic role of residual thrombus burden (rTB), after manual thrombectomy, in patients undergoing primary percutaneous coronary intervention with routine manual thrombectomy in the TOTAL trial (Thrombectomy Versus PCI Alone).

METHODS

This is a single-arm analysis of patients from the TOTAL trial who underwent routine manual aspiration thrombectomy. The rTB was quantified by an angiographic core laboratory using the Thrombolysis in Myocardial Infarction criteria and validated using existing optical coherent tomography data. Large rTB was defined as grade ≥3. The primary outcome was death from cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, or new or worsening heart failure within 180 days.

RESULTS

Of 5033 patients randomized to routine thrombectomy, 2869 patients had quantifiable rTB (1014 [35%] had large rTB). Patients with large rTB were more likely to have hypertension, previous percutaneous coronary intervention, myocardial infarction, or Killip class III on presentation but less likely to have Killip class I. The primary outcome occurred more frequently in patients with large rTB, even after adjustment for known risk predictors (8.6% versus 4.6%; adjusted hazard ratio, 1.83 [95% CI, 1.34-2.48]). These patients also had a higher risk of cardiovascular death (adjusted hazard ratio, 1.83 [95% CI, 1.13-2.95]), cardiogenic shock (adjusted hazard ratio, 2.02 [95% CI, 1.08-3.76]), and heart failure (adjusted hazard ratio, 1.74 [95% CI, 1.02-2.96]) but not myocardial infarction or stroke.

CONCLUSIONS

Large rTB is a common finding in primary percutaneous coronary intervention and is associated with increased risk of adverse cardiovascular outcomes, including cardiovascular death. Future technologies offering better thrombus removal than current devices may decrease or even eliminate the risk associated with rTB. This, potentially, can turn into a strategic option to be studied in clinical trials.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01149044.

AngioJet rheolytic thrombectomy in patients with thrombolysis in myocardial infarction thrombus grade 5: an observational study

The aim of this study was to evaluate the effectiveness and safety of AngioJet rheolytic thrombectomy among patients with high thrombus burden. Routine manual thrombus aspiration in patients with ST-segment elevation myocardial infarction (STEMI) does not improve clinical outcomes and was associated with an increased rate of stroke. However, the safety of mechanical thrombus aspiration is still unknown. This was a retrospective, single-center study involving 621 patients with Thrombolysis In Myocardial Infarction thrombus grade 5. The primary outcome was the composite of major adverse cardiovascular events (MACE) within 12 months. The safety outcome was stroke within 1-year. Propensity matching score was calculated due to the significant baseline differences between the AngioJet rhelytic thrombectomy group and the routine treatment group. AngioJet rheolytic thrombectomy was performed in 117 patients. After propensity-score matching, there was no significant difference both in the incidence of MACE (11.1% vs 17.9%, hazard ratio, 1.641; 95% confidence interval [CI] 0.822 to 3.277, p = 0.161) and the incidences of stroke (1.7% vs 2.6%, hazard ratio 1.522; 95% confidence interval [CI] 0.254 to 9.107, p = 0.646) between two groups at 1-year follow-up. In patients with Thrombolysis In Myocardial Infarction thrombus grade 5, AngioJet rheolytic thrombectomy did not improve clinical outcomes at 1 year. However, AngioJet rheolytic thrombectomy did not increase the risk of stroke in patients with high thrombus burden.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Mechanism and potential treatment of the "no reflow" phenomenon after acute myocardial infarction: role of pericytes and GPR39

The "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction (AMI) but tissue perfusion is not restored, is associated with worse outcome. The mechanism of no reflow is unknown. We hypothesized that pericytes contraction, in an attempt to maintain a constant capillary hydrostatic pressure during reduced coronary perfusion pressure, causes capillary constriction leading to no reflow and that this effect is mediated through the orphan receptor, GPR39, present in pericytes. We created AMI (coronary occlusion followed by reperfusion) in GPR39 knock out mice and littermate controls. In a separate set of experiments, we treated wild-type mice undergoing coronary occlusion with vehicle or VC43, a specific inhibitor of GPR39, before reperfusion. We found that no reflow zones were significantly smaller in the GPR39 knockouts compared with controls. Both no reflow and infarct size were also markedly smaller in animals treated with VC43 compared with vehicle. Immunohistochemistry revealed greater capillary density and larger capillary diameter at pericyte locations in the GPR39-knockout and VC43-treated mice compared with controls. We conclude that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow during AMI and that smaller no reflow zones in GPR39-knockout and VC43-treated animals are associated with smaller infarct sizes. These results elucidate the mechanism of no reflow in AMI, as well as providing a therapeutic pathway for the condition.NEW & NOTEWORTHY The mechanism of "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction but tissue perfusion is not restored, is unknown. This condition is associated with worse outcome. Here, we show that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow. Smaller no-reflow zones in GPR39-knockout animals and those treated with a GPR39 inhibitor are associated with smaller infarct size. These results could have important therapeutic implications.

Outcome of manual thrombus aspiration for patients undergoing primary PCI for acute STEMI showing large thrombus burden

Background

Routine thrombus aspiration during primary PCI does not improve clinical outcomes. Although recent guidelines for management of patient presented by ST-elevation myocardial infarction treated by primary PCI does not recommend routine use of thrombus aspiration and ranking it as class III recommendation. However, there is remaining uncertainty about rule of TA in group of patients presented by STEMI and their initial coronary angiogram shows large thrombus burden as there is a logical rationale for greater benefit, and still, there are no clear guidelines for management of this group of patients; the aim of this study is to evaluate the in-hospital and short-term outcome of using manual thrombus aspiration in STEMI patients undergoing primary PCI and showing large thrombus burden.

Results

The study was prospective observational study included 209 patients referred to coronary care unit (CCU) with diagnosis of STEMI who had undergone primary PCI; their initial coronary angiography show totally occluded infarct-related artery with heavy thrombus burden. Patients were divided into 2 groups: group (B) which included 73 patients, who had undergone PTCA and manual thrombus aspiration followed by stent to culprit lesion, and group (A) which included 136 patients, who had undergone conventional PTCA and stent of culprit lesion within the period from November 2016 till July 2018. Patients had a pre-discharge echo and were followed up for 4 weeks for major adverse cardiac events (MACE) and echo repeated after 1 month of discharge.

It was found that thrombus aspiration in heavy thrombus burden cases had improved in-hospital mortality and in-hospital secondary endpoints (TIMI flow, MBG, ST-segment resolution), as well as 30-day MACE and LV systolic function.

Conclusion

In patients presented with STEMI and heavy thrombus burden culprit artery, manual thrombus aspiration has great value in reducing index hospitalization and 1 month mortality and improve TIMI flow, MBG, ST-segment resolution, and left ventricular systolic function.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Thrombus Embolisation: Prevention is Better than Cure

Thrombus embolisation complicating primary percutaneous coronary intervention in ST-elevation myocardial infarction is associated with an increase in adverse outcomes. However, there are currently no proven recommendations for intervention in the setting of large thrombus burden. In this review, we discuss the clinical implications of thrombus embolisation and angiographic predictors of embolisation, and provide an update of current evidence for some preventative strategies, both pharmacological and mechanical, in this setting.

[Deferred versus immediate stenting in patients with ST - segment elevation myocardial infarction and residual large thrombus burden reclassified in the culprit lesion]

BACKGROUND

Reclassification of a large thrombus burden is an independent predictor of major adverse cardiac events and no-reflow in patients with ST- segment elevation myocardial infarction (STEMI). Patients with a greater residual thrombus burden have worse microvascular dysfunction and greater myocardial damage.

METHODS

A retrospective analysis was performed on 833 STEMI patients who underwent primary percutaneous coronary intervention. The final residual thrombus burden was reclassified after the lesion was wired, and a thrombus aspiration or balloon dilatation was performed to restore and stabilise a thrombolysis in myocardial infarction (TIMI) 2-3 flow. Deferred stenting (DEI) was compared with immediate stenting (ISI) group, and the primary outcome was the incidence of no-/slow-reflow (TIMI ≤ 2, or TIMI 3 with myocardial blush grade < 2).

RESULTS

Overall, 47 patients (6.8%) had a residual large thrombus burden reclassified. The right coronary artery was the culprit vessel in 34 cases. More patients had coronary ectasia in the DSI group (P=.005). Fewer patients in the DSI had no-/slow-reflow (36% vs. 58%), and the myocardial blush grade 3 was more frequent in the DSI group (P=.005). After repeat coronary angiography in the DSI group, stenting was not performed in 56%, and oral anticoagulation was more frequent in the follow-up (P=.031). Major cardiac adverse events were similar between groups. There was a tendency to better left ventricular function in the DSI group (P=.056).

CONCLUSIONS

Deferred stenting may be an efficient option in STEMI patients with a residual large thrombus burden reclassified after achieving a stable TIMI 2-3 flow.

Rural-Urban Disparity in Emergency Care for Acute Myocardial Infarction in Japan

BACKGROUND

There are few reports examining regional differences between rural prefectures and metropolitan areas in the management of acute myocardial infarction (AMI) in Japan.Methods and Results:In the Rural AMI registry, a prospective, multi-prefectural registry of AMI in 4 rural prefectures (Ishikawa, Aomori, Ehime and Mie), a total of 1,695 consecutive AMI patients were registered in 2013. Among them, 1,313 patients who underwent primary percutaneous coronary intervention (PPCI) within 24 h of onset were enrolled in this study (Rural group), and compared with the cohort data from the Tokyo CCU Network registry for AMI in the same period (Metropolitan group, 2,075 patients). The prevalence of direct ambulance transport to PCI-capable facilities in the Rural group was significantly lower than that in the Metropolitan group (43.8% vs. 60.3%, P<0.01), which resulted in a longer onset-to-balloon time (OTB: 225 vs. 210 min, P=0.02) and lower prevalence of PPCI in a timely fashion (OTB ≤2 h: 11.5% vs. 20.7%, P<0.01) in the Rural group. Multivariate analysis revealed that direct ambulance transport was the strongest predictor for PPCI in a timely fashion (odds ratio=4.13, P<0.001).

CONCLUSIONS

AMI patients in rural areas were less likely to be transported directly to PCI-capable facilities, resulting in time delay to PPCI compared with those in metropolitan areas.

Thrombus aspiration and prehospital ticagrelor administration in ST-elevation myocardial infarction: Findings from the ATLANTIC trial

BACKGROUND

The potential interactions between prehospital (pre-H) ticagrelor administration and thrombus aspiration (TA) in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) have never been studied. Therefore, we evaluated the potential benefit of TA and pre-H ticagrelor treatment in patients enrolled in the ATLANTIC trial (NCT01347580).

METHODS

This analysis included 1,630 patients who underwent primary PCI. Multivariate analysis was used to explore the potential association of TA and pre-H treatment to clinical outcomes. Potential interactions between TA and pre-H ticagrelor were also explored.

RESULTS

A total of 941 (57.7%) patients underwent TA. In adjusted multivariate logistic model, pre-H ticagrelor treatment was significantly associated with less frequent new MI or definite stent *thrombosis (ST) (odds ratio [OR] 0.43, 95% CI 0.20-0.92, P=.031), or definite ST (OR 0.26, 95% CI 0.07-0.91, P=.036) at 30 days. Patients treated with TA had higher frequency of Thrombolysis in Myocardial Infarction (TIMI) flow 0-1 compared with no-TA group (80.7% vs 51.9%, P<.0001). TA when also adjusted for TIMI flow 0-1 showed significant association only for higher bailout use of glycoprotein IIb/IIIa inhibitors (OR 1.72, 95% CI 1.18-2.50, P=.004) and more frequent 30-day TIMI major bleeding (OR 2.92, 95% CI 1.10-7.76, P=.032). No significant interactions between TA and pre-H ticagrelor were present for the explored end points.

CONCLUSIONS

TA when left to physicians' discretion was used in high-risk patients, was associated with bailout use of glycoprotein IIb/IIIa inhibitors and TIMI major bleeding, and had no impact on 30-day clinical outcomes. Conversely, pre-H ticagrelor treatment predicted lower 30-day rates of ST or new MI without interaction with TA.

Sex Differences in Clinical Outcomes After Premature Acute Coronary Syndrome

BACKGROUND

Over past decades, the incidence of acute coronary syndrome (ACS) has increased in young women, and greater mortality rates after discharge were observed among young women vs men. We revisited this issue with contemporary data from the Gender and Sex Determinants of Cardiovascular Disease: From Bench to Beyond Premature Acute Coronary Syndrome (GENESIS-PRAXY), a multicentre prospective cohort study.

METHODS

One thousand two hundred thirteen patients were enrolled in GENESIS-PRAXY from 26 centres across Canada, the United States, and Switzerland between January 2009 and April 2013. We assessed major adverse cardiac events (MACE) and mortality over 12 months after ACS. The role of sex as a predictor of outcomes was determined with Cox proportional hazard regression analysis.

RESULTS

We included 1163 patients with complete data. The occurrence of MACE was 9% and 8% in women and men, respectively (P = 0.75), and 1% of women and men died during follow-up. In adjusted models, there was no sex difference in the risk of MACE or mortality. The proportion of patients with all-cause rehospitalization was higher in women (13%) compared with men (9%; P = 0.006), but cardiac rehospitalization rates were similar in both sexes regardless of ACS type. Among first rehospitalizations, the majority was classified as cardiac related (69%), with chest pain or angina (28%) and myocardial infarction (19%) reported as the most common reasons for first rehospitalization.

CONCLUSIONS

Women were more likely than men to be rehospitalized for all causes but not for a cardiac cause. In contrast to earlier studies, men and women had similar mortality and MACE outcomes at 1 year.

Acute Myocardial Infarction/Thrombectomy

This article focuses on specialized techniques and devices used in the most challenging cases of acute myocardial infarction. Areas where high-quality evidence is either clear or absent are avoided. Controversies in the use of support or thrombectomy devices, the addition of adjunct pharmacology, and the decision to treat nonculprit lesions are discussed. Recent years have seen a shift in guidelines to downgrading the use of assist devices in cardiogenic shock and aspiration thrombectomy, whereas consideration of nonculprit coronary intervention has been revived. These changes come in the wake of a series of large, practice-changing clinical trials.

Manual Aspiration Thrombectomy in Acute Myocardial Infarction: A Clinical Experience

Multiple clinical studies have failed to establish the role of routine use of thrombectomy in ST-elevation myocardial infarction (STEMI) patients. There is a paucity of data on the impact of thrombectomy in unselected STEMI patients outside clinical trials. We sought to evaluate the clinical variables and outcomes associated with the performance of thrombectomy in STEMI patients. We retrospectively examined the clinical outcomes in all STEMI patients who underwent successful percutaneous intervention (PCI) at our center. Patients were divided into two groups, one with patients who underwent conventional PCI and another with patients who had thrombus aspiration in addition to conventional PCI. We compared the baseline clinical characteristics, laboratory investigations, re-infarction rates, and all-cause mortality. Total 477 consecutive STEMI patients were identified. Overall, 29% (139) of the patients underwent conventional PCI and 71% (338) of the patients were treated with aspiration thrombectomy and PCI. In addition to the presence of thrombus, patients with nonanterior infarction, and patients with hemodynamic instability requiring intra-aortic balloon pump support were more likely to undergo thrombectomy. Thrombectomy was associated with higher enzymatic infarction (creatine kinase: 2,796 [2,575] vs. 1,716 [1,662]; p < 0.0001; CK-MB: 210.6 [156.0] vs. 142.0 [121.9], p < 0.0001). However, thrombectomy was not associated with any difference in 30 day reinfarction rate (3.3 vs. 2.9%, p = 0.83), mortality (5.0 vs. 7.2%, p = 0.35), or composite of death and 30 day reinfarction (7.7 vs. 9.4%, p = 0.55). We observed that STEMI patients with anterior infarction and hemodynamic instability were more likely to undergo thrombectomy during primary PCI.

Rheolityc thrombectomy in acute myocardial infarction: Effect on microvascular obstruction, infarct size, and left ventricular remodeling

OBJECTIVES

We sought to analyze whether rheolytic thrombectomy (RT) in comparison with manual thrombus aspiration (MTA) may reduce microvascular obstruction (MVO), infarct size (IS), and left ventricular (LV) remodeling in ST-elevation myocardial infarction (STEMI).

BACKGROUND

Conflicting results have been reported as to whether MTA reduces MVO and IS.

METHODS AND RESULTS

Eighty STEMI reperfused by primary angioplasty and abciximab were randomly allocated (1:1) to RT or MTA. Cardiac magnetic resonance imaging (MRI) was performed in 37 patients (19 RT) and after 1 year in 19 (9 RT); baseline, 1- and 6-month 2D-echo was performed in all patients. MVO and IS were measured 8 min after gadolinium injection with late enhancement sequences and were analyzed quantitatively at a core laboratory blinded to randomization. At baseline TIMI thrombus grade were similar (RT: 4.47 ± 0.84 vs. MTA: 4.67 ± 0.76, P = 0.453). After thrombectomy, thrombus grade decreased to 1.11 ± 1.04 in RT vs. 2.17 ± 1.29 in MTA arm (P = 0.009). RT compared with MTA did not reduced significantly myocardial IS [12.2% (6.4-22.1) vs. 19.0% (7-28.5), P = 0.224] as well as the extent of MVO [0.0% (0.0-0.17) vs. 0.6% (0.0-1.4), P = 0.117], but a trend toward a lower incidence of MVO (16% vs. 44%, P = 0.056) and a less LV remodeling rate were found in RT arm (11% vs. 24%, P < 0.140).

CONCLUSION

RT in comparison with MTA was more effective in thrombus removal, but it did not reduced significantly the IS and the extent of MVO. However, a trend toward a lower incidence of MVO and a better preservation of LV volumes were found in RT arm. © 2015 Wiley Periodicals, Inc.

Clinical efficacy of thrombus aspiration on 5-year clinical outcomes in patients with ST-segment elevation acute myocardial infarction undergoing percutaneous coronary intervention

Background

Adjunctive thrombus aspiration (TA) during primary percutaneous coronary intervention (PCI) was reported to promote better coronary and myocardial reperfusion. However, long-term mortality benefit of TA remains controversial. The objective of this study is to investigate the clinical impact of TA on long-term clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI.

Methods and Results

The CREDO-Kyoto AMI Registry is a large-scale cohort study of acute myocardial infarction patients undergoing coronary revascularization in 2005–2007 at 26 hospitals in Japan. Among 5429 patients enrolled in the registry, the current study population consisted of 3536 patients who arrived at the hospital within 12 hours after the symptom onset and underwent primary PCI. Clinical outcomes were compared between the 2 patient groups with or without TA. During primary PCI procedures, 2239 out of 3536 (63%) patients underwent TA (TA group). The cumulative 5-year incidence of all-cause death was significantly lower in the TA group than in the non-TA group (18.5% versus 23.9%, log-rank P<0.001). After adjusting for confounders, however, the risk for all-cause death in the TA group was not significantly lower than that in the non-TA group (hazard ratio: 0.90, 95% CI: 0.76 to 1.06, P=0.21). The adjusted risks for cardiac death, myocardial infarction, stroke, and target-lesion revascularization were also not significantly different between the 2 groups.

Conclusions

Adjunctive TA during primary PCI was not associated with better 5-year mortality in STEMI patients.

Interventional Strategies in Thrombus Management for ST Elevation Myocardial Infarction

The major limitation of modern primary percutaneous coronary intervention (PPCI) is distal embolisation of thrombus and microvascular obstruction. Microvascular flow, as measured by myocardial blush grade (MPG), predicts mortality after PPCI. Despite initial enthusiasm, current evidence does not support routine use of Intracoronary over intravenous glycoprotein 2b3a inhibitors during PPCI for ST elevation myocardial infarction (STEMI) to improve clinical outcomes. Manual thrombectomy (MT) improves MPG and reduces distal embolisation in meta-analyses of small trials. A single-centre trial (N=1071), the Thrombus aspiration during percutaneous coronary intervention in acute myocardial infarction study (TAPAS) trial showed a mortality reduction, which led guidelines to recommend routine manual aspiration. However, the largest randomised trial (Thrombus aspiration in ST-elevation myocardial infarction in Scandinavia [TASTE] trial, N=7021) showed no difference in mortality and only trends towards reduction in myocardial infarction (MI) and stent thrombosis. The TASTE trial had much lower than expected mortality and so was likely underpowered for modest but important treatment effects (20-30 % RRR). The Thrombectomy with PCI versus PCI alone in patients with STEMI undergoing primary PCI (TOTAL) trial (N=10,700) will determine if MT reduces important clinical events during PPCI. Thrombus management remains an important area of research in STEMI.

Thrombus aspiration in acute myocardial infarction: Rationale and indication

Reperfusion of myocardial tissue is the main goal of primary percutaneous coronary intervention (PPCI) with stent implantation in the treatment of acute ST-segment elevation myocardial infarction (STEMI). Although PPCI has contributed to a dramatic reduction in cardiovascular mortality over three decades, normal myocardial perfusion is not restored in approximately one-third of these patients. Several mechanisms may contribute to myocardial reperfusion failure, in particular distal embolization of the thrombus and plaque fragments. In fact, this is a possible complication during PPCI, resulting in microvascular obstruction and no-reflow phenomenon. The presence of a visible thrombus at the time of PPCI in patients with STEMI is associated with poor procedural and clinical outcomes. Aspiration thrombectomy during PPCI has been proposed to prevent embolization in order to improve these outcomes. In fact, the most recent guidelines suggest the routine use of manual aspiration thrombectomy during PPCI (class IIa) to reduce the risk of distal embolization. Even though numerous international studies have been reported, there are conflicting results on the clinical impact of aspiration thrombectomy during PPCI. In particular, data on long-term clinical outcomes are still inconsistent. In this review, we have carefully analyzed literature data on thrombectomy during PPCI, taking into account the most recent studies and meta-analyses.

Clinical and procedural predictors of no-reflow in patients with acute myocardial infarction after primary percutaneous coronary intervention

BACKGROUND

The treatment of acute myocardial infarction (AMI) is thought to restore antegrade blood flow in the infarct-related artery (IRA) and minimize ischemic damage to the myocardium as soon as possible. The present study aimed to identify possible clinical predictors for no-reflow in patients with AMI after primary percutaneous coronary intervention (PCI).

METHODS

A total of 312 consecutive patients with AMI who had been treated from January 2008 to December 2010 at the Cardiology Department of East Hospital, Tongji University School of Medicine were enrolled in this study. Inclusion criteria were: (i) patients underwent successfully primary PCI within 12 hours after the appearance of symptoms; or (ii) patients with ischemic chest pain for more than 12 hours after a successful primary PCI within 24 hours after appearance of symptoms. Exculsion criteria were: (i) coronary artery spasm; (ii) diameter stenosis of the culprit lesion was <50% and coronary blood flow was normal; (iii) patients with severe left main coronary or multivessel disease, who had to require emergency revascularization. According to thrombolysis in myocardial infarction (TIMI), the patients were divided into a reflow group and a no-reflow group. The clinical data, angiography findings and surgical data were compared between the two groups. Univariate and multivariate logistic regressions were used to determine the predictors for no-reflow.

RESULTS

Fifty-four (17.3%) of the patients developed NR phenomenon after primary PCI. Univariate analysis showed that age, time from onset to reperfusion, systolic blood pressure (SBP) on admission, Killip class of myocardial infarction, intra-aortic balloon pump (IABP) use before primary PCI, TIMI flow grade before primary PCI, type of occlusion, thrombus burden on baseline angiography, target lesion length, reference luminal diameter and method of reperfusion were correlated with no-reflow (P<0.05 for all). Multiple logistic regression analysis identified that age >65 years [OR=1.470, 95% confidence interval (CI) 1.460-1.490, P=0.007], long time from onset to reperfusion >6 hours (OR=1.270, 95%CI 1.160-1.400, P=0.001), low SBP on admission <100 mmHg (OR=1.910, 95%CI 1.018-3.896, P=0.004), IABP use before PCI (OR= 1.949, 95%CI 1.168-3.253, P=0.011), low (≤1) TIMI flow grade before primary PCI (OR=1.100, 95%CI 1.080-1.250, P<0.001), high thrombus burden (OR=1.600, 95%CI 1.470-2.760, P=0.030), and long target lesion (OR=1.948, 95%CI 1.908-1.990, P=0.019) on angiography were independent predictors of no-reflow.

CONCLUSION

The occurrence of no-reflow after primary PCI for acute myocardial infarction can predict clinical, angiographic and procedural features.

Implications of ventricular arrhythmia “bursts” with normal epicardial flow, myocardial blush, and ST-segment recovery in anterior ST-elevation myocardial infarction reperfusion: A biosignature of direct myocellular injury “downstream of downstream”

Aims:

Establishing epicardial flow with percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is necessary but not sufficient to ensure nutritive myocardial reperfusion. We evaluated whether adding myocardial blush grade (MBG) and quantitative reperfusion ventricular arrhythmia “bursts” (VABs) surrogates provide a more informative biosignature of optimal reperfusion in patients with Thrombolysis in Myocardial Infarction (TIMI) 3 flow and ST-segment recovery (STR).

Methods and results:

Anterior STEMI patients with final TIMI 3 flow had protocol-blinded analyses of simultaneous MBG, continuous 12-lead electrocardiogram (ECG) STR, Holter VABs, and day 5–14 SPECT imaging infarct size (IS) assessments. Over 20 million cardiac cycles from >4500 h of continuous ECG monitoring in subjects with STR were obtained. IS and clinical outcomes were examined in patients stratified by MBG and VABs. VABs occurred in 51% (79/154) of subjects. Microcirculation (MBG 2/3) was restored in 75% (115/154) of subjects, of whom 53% (61/115) had VABs. No VABs were observed in subjects without microvascular flow (MBG of 0). Of 115 patients with TIMI 3 flow, STR, and MBG 2/3, those with VABs had significantly larger IS (median: 23.0% vs 6.0%, p=0.001). Multivariable analysis identified reperfusion VABs as a factor significantly associated with larger IS ( p=0.015).

Conclusions:

Despite restoration of normal epicardial flow, open microcirculation, and STR, concomitant VABs are associated with larger myocardial IS, possibly reflecting myocellular injury in reperfusion settings. Combining angiographic and ECG parameters of epicardial, microvascular, and cellular response to STEMI intervention provides a more predictive “biosignature” of optimal reperfusion than do single surrogate markers.

Lessons from primary PCI practice for the next decade

Primary percutaneous coronary intervention (PPCI) is the reperfusion treatment of choice for acute ST-elevation myocardial infarction with studies having demonstrated improved outcomes with PPCI over thrombolysis. Its use has increased substantially over the last decade, overtaking thrombolytic therapy in many countries. This has been paralleled with advances in adjunctive technology and pharmacological therapy to further improve outcome, but challenges remain for PPCI practitioners. The evidence behind PPCI is reviewed at every stage of the patient's journey.

Coronary thrombus in patients undergoing primary PCI for STEMI: Prognostic significance and management

Acute ST-elevation myocardial infarction (STEMI) usually results from coronary atherosclerotic plaque disruption with superimposed thrombus formation. Detection of coronary thrombi is a poor prognostic indicator, which is mostly proportional to their size and composition. Particularly, intracoronary thrombi impair both epicardial blood flow and myocardial perfusion, by occluding major coronary arteries and causing distal embolization, respectively. Thus, although primary percutaneous coronary intervention is the preferred treatement strategy in STEMI setting, the associated use of adjunctive antithrombotic drugs and/or percutaneous thrombectomy is crucial to optimize therapy of STEMI patients, by improving either angiographical and clinical outcomes. This review article will focus on the prognostic significance of intracoronary thrombi and on current antithrombotic pharmacological and interventional strategies used in the setting of STEMI to manage thrombotic lesions.

Angiographic and Clinical Impact of Successful Manual Thrombus Aspiration in Diabetic Patients Undergoing Primary PCI

Background. Diabetes mellitus is associated with worse angiographic and clinical outcomes after percutaneous coronary intervention (PCI). Aim. To investigate the impact of manual thrombus aspiration on in-stent restenosis (ISR) and clinical outcome in patients treated by bare-metal stent (BMS) implantation for ST-segment elevation myocardial infarction (STEMI). Methods. 100 diabetic patients were prospectively enrolled. They were randomly assigned to undergo either standard primary PCI (group A, 50 patients) or PCI with thrombus aspiration using Export catheter (group B, 50 patients). The primary endpoint was the rate of eight-month ISR. The secondary endpoint included follow-up for major adverse cardiac events (MACE). Results. Mean age of the study cohort was 59.86 ± 8.3 years, with 64 (64%) being males. Baseline characteristics did not differ between both groups. Eight-month angiogram showed that group B patients had significantly less late lumen loss (0.17 ± 0.35 versus 0.60 ± 0.42 mm, P < 0.001), with lower incidence of ISR (4% versus 16.6%, P < 0.001). There was a trend towards lower rate of MACE in the same group of patients. Conclusion. In diabetic patients undergoing primary PCI, manual thrombus aspiration (compared with standard PCI) was associated with better ISR rate after BMS implantation.

The "no reflow" phenomenon following acute myocardial infarction: mechanisms and treatment options

If 'no reflow' is observed within 45min of reperfusion using balloon angioplasty or stent, it is probably related to microthromboemboli, which may also contribute to the extension of the 'no reflow' zone by converting 'low reflow' areas into necrotic ones even when reperfusion is achieved more than 45min after the onset of coronary occlusion. Since 'no reflow' is noted when 45min of coronary occlusion has elapsed even in the absence of a thrombus, 'no reflow' late after reperfusion is predominantly due to tissue necrosis and unlikely to be resolved unless methods to reduce infarct size are used. Attempts at reducing the intracoronary thrombus burden during a coronary procedure for acute myocardial infarction (AMI) have been shown to reduce 'no reflow' and improve clinical outcome, as has the use of potent antithrombotic agents. Drugs that can reduce infarct size, when given intracoronary or intravenous in conjunction with a coronary intervention during AMI can also reduce 'no reflow' and improve outcomes in patients with AMI. The prognostic importance of 'no reflow' post-AMI is related to its close correspondence with infarct size. Although several imaging and non-imaging methods have been used to assess 'no reflow' or 'low reflow' myocardial contrast echocardiography remains the ideal method for its assessment both in and outside the cardiac catheterization laboratory.

Use of Thrombectomy Devices in Primary Percutaneous Interventions for ST-elevation Myocardial Infarction - An Update

Primary percutaneous coronary intervention (PPCI) is the preferred reperfusion modality in patients with ST-elevation myocardial infarction (STEMI). While PPCI is highly effective in achieving epicardial coronary reperfusion, a significant proportion of patients fail to achieve adequate myocardial reperfusion. This is in part due to the distal microembolisation of thrombus and plaque debris during PCI. Recognition of this has led to the development of a number of devices with different mechanisms of action that aim to reduce such distal embolisation and therefore improve end myocardial perfusion. Study results of thrombectomy devices however have been largely inconsistent, especially about clinical outcome data, and several meta-analyses have been carried out as a result. This review aims to critically analyse the literature data on thrombectomy during PPCI, taking into account the most recent studies and the latest meta-analyses looking to see whether thrombectomy use is associated with improved outcomes.